OBJECTIVES: 1. To evaluate a technique for transplantation of immediately vascularized, intact segmental pancreatic grafts to an extraperitoneal site in dogs: suppression or elimination of pancreatic graft exocrine function will be induced by injection of neoprene into the pancreatic duct totally occluding the entire ductal system, thus obviating the need for duct drainage; 2> To determine in rats and dogs whether there is a difference in the functional survival or susceptibility to rejection of: (a) an immediately vascularized intact pancreatic graft and (b) a free graft of an equivalent quantity of islet tissue transplanted to diabetic recipients. The short- and long-term effect of neoprene injection into the pancreatic duct will be evaluated in dogs with the pancreas left in situ. In addition, immediately vascularized, neoprene duct-injected segmental pancreatic allografts will be transplanted to the iliac fossa of immuno-suppressed and nonimmunosuppressed dogs made diabetic by total pancreatectomy; the graft functional survival and the technical complication will be compared to diabetic animals receiving duct-ligated and nonligated segmental pancreatic allografts without neoprene injection. Lewis rats with streptozotocin induced diabetes will receive either: (a) immediately vascularized segmental pancreatic allografts, or (b) free grafts of allogenic islet tissue embolized via the portal vein; plasma glucose levels will be measured daily, and the functional survival of the two types of grafts determined and compared in immunosuppressed and nonimmunosuppressed recipients. Comparison will also be made in dogs as to the functional survival of immediately vascularized segmental pancreatic allografts and free allografts of dispersed pancreatic tissue transplanted to the spleen of totally pancreatectomized recipients. If there are differences in susceptibility to rejection of pancreatic endocrine tissue transplanted by the two techniques, the differences will influence the approach to clinical transplantation for diabetes mellitus. If transplantation of immediately vascularized, neoprene duct-injected segmental pancreatic allografts proves to be a safe and effective technique of transplantation without the need for complicated manuevers to establish duct drainage, this approach can also be considered for clinical trials.